One of my earliest dreams was to cross the Atlantic Ocean on a ship. In 2015, I did it.
There are specialty travel agents that arrange passage on cargo carriers. I worked with an agent in London who told me about an smaller ship that sailed from London across the Englis Channel and then up the River Seine to Rouen, France before turning around and headed to the Caribbean.
It was short notice and I needed to get a few shots plus a doctors note that I was healthy before approval was granted. I flew to London and met the ship a few days later.
I loved it. The officers were Romanian and the crew were from the Philippines. Fantastic food and gracious crew who always answered my many questions without annoyance.
Plus, going through four-meter waves in the middle of the Atlantic was an experience.